The invention relates to a separator cell for pressure filtration and reverse osmosis.
Since the separator cell according to the invention can be used for filtration as well as permeation processes, the term "filtrate" is employed herein also in the sense of "permeate."
The known separator cells for pressure filtration and reverse osmosis are composed of a two-part pressure housing. Such a device is, for example, a TCF-10 model, manufactured by Amicon Corporation, Lexington, Massachusetts. In the known device membrane supported by a filter support is inserted between the upper and lower housing parts and lies against a flow channel which is open toward this membrane and whose ends are connected with an intake pipe and with a concentrate discharge pipe.
The filtrate is discharged through a channel which is connected with the rear side of the membrane. The substance mixture is conducted through the intake pipe perpendicularly onto the membrane while it is conducted away from the membrane, again perpendicularly, through the concentrate discharge pipe. To protect the membrane against wear caused by the inflowing fluid, baffle plates are provided between the intake pipe and the membrane. The flow channel lying against the membrane conducts the fluid over the membrane on a spiral-shaped path. Since the stream in the spiral-shaped flow channel is subjected to centrifugal forces, secondary streams develop which influence the filtration and permeation process in that they reduce its output. Moreover, during ultrafiltration and microfiltration, demixing occurs between the carrier fluid and the suspended particles--if there are differences in density between the particles and the fluid--and this results in polarization phenomena and deposits on the membrane surface. Deposits cause clogging which reduces the throughput capability of the membrane and shortens the service life of the separator cells.